Tehran University Medical Journal

Background: Renal artery stenosis (RAS) is a known cause of secondary hypertension and renal failure. The most patients with renal artery stenosis are asymptomatic. So, the exact prevalence of this disease is unknown. The gold standard of diagnosis of RAS is renal angiography that is an expensive somewhat hazardous procedure and may revealed nothing. The aim of this study was to develop a simple risk model score to predict significant RAS based on known risk factors. This may enable us to select patients with high probability of having RAS to perform angiography.
Methods: A total of 4177 patients whom underwent renal angiography from April 2001 to March 2016, were randomly assigned to a development and a validation dataset in ratio of 2:1 respectively. The clinical and laboratory data of patients were analyzed by multivariate regression analysis. The factors of female sex, history of hypertension and glomerular filtration rate were determined as predicting factors and they were assigned a weighted integer, the sum of the integers was a total risk score for each patient. This model was examined at validation set.
Results: We retrospectively evaluated all patients undergoing renal artery angiography since 15 years ago. We extracted all risk factors of RAS including age, sex, height, weight, and history of diabetes, hypertension and hyperlipidemia. We also looked at coronary or peripheral vascular diseases and presence of heart failure. The age of patients was 63.5±11.2 years and 40% of the patients were female. The significant RAS was defined as 70% or more narrowing of renal artery. The prevalence of renal artery stenosis was 14.4% and 13.5% in development and validation dataset respectively. The area under curve and confidence interval for final mode in development dataset was 67.9% (65.0-70.8%). The rates of RAS increased with increasing risk score. In 1402 patients in validation dataset the model showed good discrimination power (cstatistic= 0.76)
Conclusion: This model simply assesses the risk of RAS using available information. This model can be used both in clinical and research purposes. The power of model for diagnosis of RAS is estimated to be 72.6% (68.8%-76.4%).

Background: This study aimed to evaluate the carcinogenic and non-carcinogenic health risks of heavy metals in seven types of tobacco widely consumed in the east of the country through inhalation exposure.
Methods: This descriptive-analytical study was conducted from April 2022 to October 2022 in the city of Bojnord, Iran on sook of seven popular tobacco brands. Metal concentrations in sook of tobacco were determined using inductively coupled plasma-optical emission spectroscopy. In order to analyze the data and ensure the accuracy of the results, the amount of metals in the samples was repeated three times, and their average was analyzed. Monte Carlo software was used to assess possible risks.

Results: The results of this study showed heavy metal concentrations in sook tobaccos were, respectively, Fe>Zn>Mn>Ba>Pb>Ni>Cu>Mo>Cr>As>Cd. The concentration of heavy metals such as arsenic, cadmium and molybdenum in Alrah brand tobacco was higher than other types of tobacco. So that the amounts of heavy metals including arsenic, cadmium and molybdenum for this brand were 14.2±0.05, 10.4±0.06 and 11.6±0.04 micrograms per gram, respectively. The hazard index (HI) values for different types of tobacco, including Al-Rah, Amordadsub, Al-Fakher, Al-Rubi, Mazaya, traditional flavorless, and Nakhle, were 2.64, 2.41, 2.05, 1.7, 1.49, 1.46, and 1.44, respectively. The lifetime cancer risk (ILCR) for Amordadsub, Al-Rah, Nakhla, Mazaya, Al-Rubi, Al-Fakher, and traditional flavorless tobaccos was 2.8×10-3, 2.43×10-3, 1.72×10-3, 1.58×10-3, 1.43×10-3, 9.58×10-4, and 8.08×10-4, respectively. Lead in Alrah tobacco sook had the highest non-carcinogenic risk value with a value of 1.59. Conclusion: According to the obtained results, Alrah tobacco sook has a higher cancer and non-cancer risk than regular tobacco and can cause non-carcinogenic and carcinogenic risks for consumers. Thus, it is necessary to regularly monitor the quality of prevalent tobacco to reduce delete human health risks.